Actuating mechanism



Nov. 3, 1953 E. J. DILLMAN ACTUATING MECHANISM Filed March 23, 1948 53 G n l 2 8 7 0 4 1 2 INVENTOR- W 0% BY W KM Jug ATTORNEY Patented Nov. 3, 1953 ACTUATIN G MECHANISM Earnest J. Dillman, Detroit, Mich, assignor to Detroit Controls Corporation, a corporation of Michigan Application March 23, 1948, Serial No. 16,541

7 Claims. (01. 137-789) This invention relates to new and useful improvements in actuating mechanisms.

One of the objects of this invention is to provide a novel actuating mechanism.

Another object is to provide a novel power element for use in an actuating mechanism.

Another object is to provide an actuating mechanism having a novel power element and utilizing a novel thrust transmitting septum.

Another object is to provide an actuating mechanism having a novel power element including a hollow cylindrical septum operable to invert upon itself for movement of a piston member.

Another object is to provide a hollow cylindrical septum for a power element of an actuating mechanism and having a means to prevent the end wall of the septum from folding upon itself upon application of pressure thereto.

Other objects will become apparent from time to time throughout the specification and claims as hereinafter related.

This invention consists in the new and improved construction and combination of parts and in their cooperative relation to each other to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings to be taken as part of the specification, there is clearly and fully illustrated one preferred embodiment of this invention in which drawings Figure l is a view in vertical cross-section of an actuating mechanism embodying this invention,

Fig. 2 is a view in vertical section of the actuating mechanism shown in a partially operated position but showing the septum and the end of the actuating piston in full elevation, and

Fig. 3 is a view in vertical section of the actuating mechanism in a fully operated position.

Referring to the drawings by characters of reference, there is shown an actuating mechanism l comprising a casing '2 having a cylindrical cavity 3 therein with an open end portion t. There is an inlet passageway 55 in the lower wall of the casing 2 which communicates through an aperture t with the cavity 3. The open end portion 41 of the casing 2 has an outturned flange portiontion the shape of a hollow cylinder having a closed end wall l5 and having a flange l6 extending laterally outward around its open end. The septum end wall i5 has a plug portion ll extending inward therefrom and has a reinforcing thickness l8 centrally positioned on the outer surface thereof. The septum M encloses the end portion of the piston 42 which extends into the cylindrical cavity 3 and the plug portion ll of the end wall extends into a cavity in the end of the piston i2, the plug portion ii being operable to hold the end wall l5 centered relative to the piston H2. The septum flange i6 is positioned on the annular shoulder 9 of the casing 2 and is held compressively in position by the guide member flange portion II. The upturned flange portion 8 of the casing 2 has an inturned flange portion i 9 which holds the flange l i of the guide member it and the flange It of the septum i l compressively in position. The septum flange it has a downwardly facing annular rim and an upwardly facing annular rim which rims fit into grooves on the annular shoulder 9 in the casing and the flange portion i l of the guide member Iii respectively and when held in compression are operable to prevent leakage from the cylindrical cavity 3. There is a tube or conduit 26 extending from the inlet passageway 5 and operable to transmit fluid pressure to the cylindrical cavity 3, for example, from a thermostatic power element bulb ii.

The actuating mechanism so far described is shown operatively connected for actuating a control mechanism. The piston i2 has an annular shoulder 22 on which is positioned a collar member 23 having an annular groove therein for receiving one end ofa spring 24. The other end of the spring 24% is supported by the annular shoulder of a pivoted actuating member 25 which would normally be pivoted on a lever for moving a valve or switch or the like. On the other side of the pivoted member 25 there is another spring 25 supported by an annular shoulder of the pivoted member and by a spring supporting member 2?. The spring supporting member 2': has a centrally positioned bore extending partiallyrtherethrough in which is positioned the abutment portion 28 of a screw adjustment member it, the operation of which should be obvious to one skilled in the art.

In operation this invention functions as follows:

In Fig. 1 the operating piston and septum are shown in initial position with the pressure in the cavity 3 being low. As the pressure in the cavity 3 is increased such as by application of heat to the thermostatic bulb element 2|, the end wall 25 of the septum l4 will begin to move longitudinally of the piston 2| thereby moving the piston. As pressure in the cavity 3 is further increased the end wall 15 of the septum M will begin to move inside the side walls of the septum thereby causing the septum to begin to invert as is shown in Fig. 2. As further pressure is applied, the end wall IE will move completely through to a point substantially in line with the septum flange I6 at which point the side walls of the septum will be completely folded back or inverted within themselves. In the past there have been many attempts to make actuating devices utilizing cylindrical septa of this type, the walls of which can invert but none of them have proved to be very satisfactory. One of the principal objections to a septum which moves to an inverted position is that in older types at some point in their movement a portion of the septum wall would reach a position where there would be no member directly backing up the septum and hence there is a tendency upon use of such a septum with high pressures for the septum to blow out at such an un'backed position. Another objection which has been found in the use of earlier septa of this type is that there is a tendency upon the application of pressure for the septum to fold upon itself along its closed end wall and upon return of the piston to its initial position the folded end wall portion tends to stick with the result that the piston must push its way into the space of the folded end wall, this usually resulting in stretching or tearing of the septum. These objections and others have been overcome in this form of actuating device.

The stiifening portion I 8 of the septum end wall acts to prevent the end wall from folding upon itself upon application of pressure for moving the piston. The plug member I! functions to keep the end wall of the septum centered relative to the operating piston so that the folding of the septum walls upon movement will be along the side wall portion or edge of the end wall portion. Since the septum side walls are restrained by the comparatively narrow clearance between the piston and the wall of the cylindrical cavity 3, the side wall of the septum is prevented from folding upon itself upon movement of the piston l2. It is then seen that upon application of pressure within the cavity 3 and movement of the septum end wall l5, since the side wall portion of the septum is restrained from folding upon itself, the walls of the septum must invert through the steps of operation as shown in Figs. 2 and 3.

The combination of the actuating mechanism l with the device to be actuated such as the pivoted member 25 is shown merely to illustrate one of the many possible utilizations of this actuating mechanism. In the combination shown, the movement of the piston 12 acts through the spring 24 and the pivoted member 25 against the force of the spring 26. Since the force of the spring 26 can be varied by the screw adjustment member 29, such adjustment will vary the pressure increase in the cavity 3 required to move the piston l2, and in the case of a thermostatic actuating means such as the bulb element 2! such variation of spring tension by the adjustment member 29 will vary the temperature of response of the actuated device.

Having thus described the invention what is claimed and is desired to be secured by Letters Patent of the United States is:

1. An actuating mechanism comprising a casing, a passageway opening into said casing, a piston slidably fitting and guided in said passageway and extending into said casing, said piston having an end cavity, a hollow septum member having a closed end wall and fitting around said piston and having its open end portion secured and sealed around the edge of said passageway, said septum being operable to move and partially fold upon itself in response to pressure within said casing thereby to move said, piston, and means operable to hold said septum end wall against lateral movement during movement of said piston, said last-named means including a plug portion on said end wall cooperating with said piston cavity.

2. An actuating mechanism comprising a casing containing a fluid, means forming an end wall for said casing, a passageway opening through said end wall into said casing, a piston slidably fitting and guided in said passageway and'extending into said casing, a hollow cylindrical septum member having a closed end wall and a peripheral flange around the open end thereof, said septum member fitting around said piston and having said flange secured and sealed against said end wall around the edge of said passageway, said septum end wall having a central portion sufficiently thickened so that upon application of fluid pressure thereto said central portion will not fold upon itself, said thickened end wall portion terminating a predetermined distance inwardly from the edge of said septum end wall, and said septum being operable to move and to fold upon itself at least partially along the side wall thereof and along the edge of said thickened end wall portion upon increase of fluid pressure within said casing thereby to move said piston.

3. An actuating mechanism comprising a casing having a cylindrical portion and an end wall and adapted to contain a fluid, a cylindrical passageway opening through said end wall into said cylindrical portion and defining an end wall shoulder, a piston slidably fitting and guided in said passageway and extending into said cylindrical portion, a septum member having in its inert condition the shape of a hollow cylinder having a closed end wall and having a peripheral flange around the open end, said septum member fitting around said piston having its side walls substantial-1y filling the annular space between said piston and said cylindrical casing portion and having said flange secured and sealed against said end wall shoulder around said cylindrical passageway, said septum member being laterally restrained by said casing cylindrical portion and operable upon increase of fluid pressure within said casing to invert upon itself thereby to move said piston, and means operable to prevent said septum closed end wall from folding upon itself upon increase of fiuid pressure within said casing for moving said piston, said last-named means including a reinforced portion on said septum end wall.

4. An actuating mechanism comprising a casing having a cylindrical portion and adapted to contain a fluid, a cylindrical passageway opening into said cylindrical portion, a piston slidably fitting and guided in said passageway and extending into said cylindrical portion, a septum member having in its inert condition the shape of a hollow cylinder closed at one end, said septum member fitting around said piston having its side walls substantially filling the annular space between said piston and said cylindrical casing portion and having its open end portion secured and sealed around said cylindrical passageway, said septum member being laterally restrained by said casing cylindrical portion and operable upon increase of fluid pressure within said casing to invert upon itself thereby to move said piston, said piston having a cavity in its end portion, said septum end wall having a reinforcing thickness on the outer central surface portion thereof and having a plug portion extending from the inner surface and cooperable with said piston cavity, and said reinforcing thickness and plug portion being operable to keep said end wall centered relative to said piston and to prevent said end wall from folding upon itself upon increase of fluid pressure within said casing for moving said piston.

5. An actuating mechanism comprising a casing having a cylindrical cavity therein with an open end having an inlet passageway to said cavity for admission of fluid under pressure, a guide member having an annular flange around its base and closing said casing open end and having a cylindrical guide passageway extending longitudinally therethrough and opening into said cavity, said casing having an outturned annular flange around said open end and having an upturned portion forming an annular shoulder for supporting said guide member flange, a piston slidably guided in said guide passageway and extending into said casing, a septum having in its inert condition the shape of a hollow cylinder with one end closed and having an annular outturned flange around its open end, said septum enclosing the end of said piston extending into said casing and having its flange compressively secured between said guide member flange and said casing annular shoulder, said casing flange upturned portion having an inturned portion compressively securing said guide member flange and said septum flange against said casing shoulder, said septum sealing said casing against leakage through said guide passageway and around said guide member flange, and said septum being op erable to move and partially fold upon itself upon increase of fluid pressure within said casing thereby to move said piston.

6. An actuating mechanism comprising a casing having a cylindrical cavity therein with an open end and having an inlet passageway to said cavity for admission of fluid under pressure, a guide member having an annular flange around its base and closing said casing open end and having a cylindrical guide passageway extending longitudinally therethrough and opening into said cavity, said casing having an outturned annular flange around said open end and having an upturned portion forming an annular shoulder for supporting said guide member flange, a piston slidably guided in said guide passageway and extending into said casing, a septum having in its inert condition the shape of a hollow cylinder with one end closed and having an annular outturned flange around its open end, said septum enclosing the end of said piston extending into said casing and having its flange compressively secured between said guide member flange and said casing annular shoulder, said casing flange upturned portion having an inturned portion compressively securing said guide member flange and said septum flange against said casing shoulder, said septum sealing said casing against leakage through said guide passageway and around said guide member flange, said piston having a central cavity in its end portion within said casing, said septum end wall having a reinforcing thickness centrally on the outer surface thereof and having a plug portion extending inwardly from the central portion of the inner surface thereof and extending into said piston cavity, said reinforcing thickness and said plug portion being operable to keep said septum end wall centered relative to said piston and to prevent said septum end wall from folding upon itself during movement of said piston by increased fluid pressure, and said septum side Walls being laterally restrained by said casing so that upon increase of fluid pressure in said casing the end wall of the septum may move longitudinally and causing the walls to invert upon themselves substantially along the edge of the septum end wal1 and thereby to move said piston.

7. A sealing means comprising a cylindrical cup-like septum member of flexible material capable of bending upon itself, said member having a lateral surrounding flange at its open end, a circular reinforcing portion on the end wall of said member extending externally therefrom and having an edge spaced inward-1y a predetermined distance from the edge of said end wall, and a plug portion within said member spaced from the side walls thereof and extending internally from said end wall.

EARNEST J. DILLMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,034,538 'Schnell Mar. 17, 1936 2,094,191 Sauzede Sept. 28, 1937 2,125,262 Hennecke July 26, 1938 2,178,953 Chilton Nov. 7, 1939 2,229,057 Dick Jan. 21, 1941 

